Functions - YOKOGAWA WT110 User Manual

1.2

Functions

Input Functions
Display Functions
Computing Functions
1-2
Voltage and Current Input Sections
A voltage or current supplied to each input terminal is normalized then sent to the A/D
converter, where the voltage or current is converted into digital signals. The digital signals are
then sent via photo-isolator to a 16-bits high-speed DSP (Digital Signal Processor) or CPU,
where computation of the measured value is carried out.
Frequency Measuring Range
Measurement of DC voltage, current and power as well as AC voltage and current in the
frequency range 10Hz to 50kHz.
Filter
This instrument carries out various measurements after synchronizing the frequency of the input
signals. Therefore, correct measurements are necessary. Thus, a filter is being applied to the
frequency measurement circuit to eliminate noise of waveforms, such as inverted and distortion
waveforms.
Wiring Method
The input units for voltage or current measurement are located on the rear panel of this
instrument. These units are called input elements. The number of input elements depends on the
model, and the possible wiring methods are as follows. The wiring method demonstrates the
circuit configuration to measure voltage, current and power and this circuit configuration varies
by phase and number of electrical wires.
model number of elements
253401 1
253502 2
253503 3
This function enables display of measured/computed values using three red high-intensity 7-
segment LED displays. A total of three values can be displayed at once.
Apparent Power, Reactive Power, Power Factor and Phase Angle
Based on the measurement values of voltage, current and active power, the values of apparent
power, reactive power, power factor and phase angle can be computed.
Scaling Function
When performing voltage or current measurements with an external PT, CT, shunt, external
sensor (clamp) or such connected, you can set a scaling factor to the primary/secondary ratio.
This is called scaling. This function enables display of the measured values of voltage, current,
active power, reactive power, integrated current and integrated power factor in terms of
primary-side values.
Averaging Function
This function is used to perform exponential or moving averaging on the measured values
before displaying them in cases where the measured values are not stable.
wiring method
single-phase, two-wire (1Φ2W)
single-phase, two-wire (1Φ2W); single-phase, three-wire
(1Φ3W); three-phase, three-wire (3Φ3W)
single-phase, two-wire (1Φ2W); single-phase, three-wire
(1Φ3W); three-phase, three-wire (3Φ3W); three-phase, four-
wire (3Φ4W); three-voltage, three-current (3V3A)
IM 253401-01E